CN107209251A - Fill level measurement apparatus - Google Patents
Fill level measurement apparatus Download PDFInfo
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- CN107209251A CN107209251A CN201580073467.1A CN201580073467A CN107209251A CN 107209251 A CN107209251 A CN 107209251A CN 201580073467 A CN201580073467 A CN 201580073467A CN 107209251 A CN107209251 A CN 107209251A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
- G01S7/28—Details of pulse systems
- G01S7/285—Receivers
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F23/00—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm
- G01F23/22—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water
- G01F23/28—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring the variations of parameters of electromagnetic or acoustic waves applied directly to the liquid or fluent solid material
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F23/00—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm
- G01F23/22—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water
- G01F23/28—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring the variations of parameters of electromagnetic or acoustic waves applied directly to the liquid or fluent solid material
- G01F23/284—Electromagnetic waves
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F23/00—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm
- G01F23/22—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water
- G01F23/28—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring the variations of parameters of electromagnetic or acoustic waves applied directly to the liquid or fluent solid material
- G01F23/296—Acoustic waves
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
- G01S13/06—Systems determining position data of a target
- G01S13/08—Systems for measuring distance only
- G01S13/10—Systems for measuring distance only using transmission of interrupted, pulse modulated waves
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/88—Radar or analogous systems specially adapted for specific applications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
- G01S7/28—Details of pulse systems
- G01S7/282—Transmitters
-
- G—PHYSICS
- G04—HOROLOGY
- G04F—TIME-INTERVAL MEASURING
- G04F5/00—Apparatus for producing preselected time intervals for use as timing standards
- G04F5/04—Apparatus for producing preselected time intervals for use as timing standards using oscillators with electromechanical resonators producing electric oscillations or timing pulses
-
- G—PHYSICS
- G04—HOROLOGY
- G04F—TIME-INTERVAL MEASURING
- G04F8/00—Apparatus for measuring unknown time intervals by electromechanical means
- G04F8/02—Apparatus for measuring unknown time intervals by electromechanical means using an electromechanical oscillator
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- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- General Physics & Mathematics (AREA)
- Computer Networks & Wireless Communication (AREA)
- Electromagnetism (AREA)
- Thermal Sciences (AREA)
- Fluid Mechanics (AREA)
- Acoustics & Sound (AREA)
- Radar Systems Or Details Thereof (AREA)
Abstract
The present invention relates to a kind of measurement apparatus (1) for the fill level (11) for being used to measure the material in container (12) based on time-of-flight, it includes being used to generating, launch and receiving measurement signal (S), and is additionally operable to the measurement signal (S) being converted into analog if signal (SIF) part (2 9), the intermediate-freuqncy signal (SIF) there is the desired signal frequency in scheduled frequency range, including the information corresponding with the fill level (11) of the material in container (12), analog-digital converter (16) is wherein provided, the analog-digital converter (16) is used for then to the intermediate-freuqncy signal (SIF) sampled, the analog-digital converter (16) is using less than intermediate-freuqncy signal (SIF) desired signal frequency sample frequency (fs)。
Description
Technical field
The present invention relates to a kind of filling water for being used to measure the fill level of the material in container based on time-of-flight
Flat measurement apparatus, it includes being used to generating, launch and receiving measurement signal, and is additionally operable to the measurement signal being converted into mould
Intend the part of intermediate-freuqncy signal, the intermediate-freuqncy signal has a desired signal frequency in scheduled frequency range, including with container
Material the corresponding information of fill level.
The present invention is more particularly directed to using ultrasonic wave and/or electromagnetic measurement signal, such as measurement apparatus based on radar
Fill level device.This fill level measurement apparatus for example by Endress+Hauser affiliated companies Prosonic,
There is provided under Micropilot and Levelflex trade marks.Fill level measurement apparatus in the sense of the present invention, which should not be understood, to be limited
In the singleton of hardware component, but it can also be the system for being spatially separating unit.Measurement apparatus can be considered as including passing
Sensor and transmitter, wherein sensor are used to the process variable of the fill level of the material in such as tank being converted into electric signal,
And wherein transmitter is used to sampling and handling the electric signal, to produce the process variable for corresponding to physical state to be measured
Value.According to circumstances, emitter can be further used for launching and/or preserve determined by process values it is for further use.
Sensor generally includes microprocessor and/or microcontroller and various other Electrical and Electronic circuits.Sensor and transmitter
It can concentrate in single single device, or they can be spatially separated from.It is spatially separating in sensor and transmitter
In the case of there is provided certain means of communication of such as cable or wireless communication means etc.Difference between emitter and sensor
Not always strictly applied, because sensor is used to pre-process measurement signal in some cases, sometimes even
Including microprocessor.
Background technology
Measurement apparatus based on ultrasonic wave and radar is all widely used in terms of measurement accuracy, reliability and cost.
These aspects of fill level measurement apparatus are at least in part by the quality and/or characteristic of the part used in the construction of device
Determine.In the market of today, fill level measurement apparatus generally filters out intermediate-freuqncy signal frequency using arrowband broadband-pass filter
Noise component(s) outside rate scope, and for using analog-to-digital conversion with high sampling rate, being sampled to intermediate-freuqncy signal
Device.High sampling rate in the sense of the present invention be twice of at least IF signal frequency but can also be much higher sample rate.
It is interpreted as the ultrasonic transducer output in ultrasonic measuring device in the intermediate-freuqncy signal in the case of ultrasonic measuring device
Signal frequency.Described in such as German Patent Publication DE00102009026885A1 for ultrasonic wave fill level dress
The application for the arrowband broadband-pass filter put, which describe bandwidth and noise in the selection and application of bandpass filter it
Between balance.The analog if signal of fill level measurement apparatus based on ultrasonic wave or radar be typically included in 0kHz and
Between 200kHz, the signal frequency particularly between 10kHz and 100kHz.
The part of high-speed AD converter and arrowband broadband-pass filter and such as logafier is typically expensive
And with high energy demand.In German Patent Publication DE102006006572A1, in principle, it is proposed that intermediate frequency letter can be carried out
Number sampling and digitlization, wherein, in order to save energy and reduce fill level measurement apparatus storage and calculate require,
It is unsatisfactory for the requirement of Nyquist-Shannon (Nyquist-Shaimon) sampling thheorem.This may be implemented so that in hits
Time difference (described value is allocated alternately to one of two groups) between word value is more than twice of inverse of IF-FRE.Nai Kui
The necessary condition of Si Te-Shannon's sampling theorem requires that sample rate is at least twice of the frequency of signal to be sampled, and due to adopting
This numeric sorting of sample value causes the necessary condition for no longer meeting Nyquist-Shaimon sampling thheorem.
The content of the invention
The purpose of the present invention is to propose to it is a kind of carried out while unnecessary cost and energy requirement is avoided it is accurate and can
The fill level measurement apparatus for the measurement leaned on.
The purpose of the present invention is to be used to measure the filling water of the material in container based on time-of-flight by a kind of
Flat measurement apparatus is come what is realized, and the measurement apparatus includes being used to generating, launch and receiving measurement signal, and is further used for
The measurement signal is converted into the part of analog if signal, the intermediate-freuqncy signal has the expectation in scheduled frequency range
Signal frequency, including the information corresponding with the fill level of the material in container, wherein provide analog-digital converter, its be used for
Intermediate-freuqncy signal is sampled afterwards, the analog-digital converter uses the sample frequency of the desired signal frequency less than intermediate-freuqncy signal.
Part for generating, launching and receiving measurement signal can include the ultrasonic transducer in such as ultrasonic unit and timing
Device electronic installation, or for the fill level measurement apparatus based on radar, including such as high-frequency generator, antenna element, letter
The part of number distributor and frequency mixer.Analog-digital converter can have more much lower than the sample rate of conventional use of analog-digital converter
Sample rate.Therefore, analog-digital converter both saves cost, saves again.
Lack sampling (undersampling) allows to being that periodic M signal carries out numeral within a predetermined period of time
Change, this is the requirement that generally meets of M signal of fill level measurement apparatus, because the rate of change of the fill level in container
Compared with the carry out speed of the measurement circulation of fill level measurement apparatus, generally it can be ignored.When intermediate frequency is owed to adopt
During sample, the frequency displacement copy or image of intermediate-freuqncy signal are produced.The image is from the downward shifted samples frequency of actual frequency.For example, with
The image of the 60kHz intermediate-freuqncy signals of 50kHz samplings is by the frequency with 10kHz.Therefore, analog-digital converter is implemented such that it
Including the predetermined sample frequency of the expected frequency relative to analog if signal.
In an advantageous embodiment, analog-digital converter is integrated in the microprocessor of measurement apparatus.Compared with conventional art,
The analog-digital converter of application integration in the microprocessor provides relatively cheap mode to if sampling.Traditionally, due to
The fact that this converter can only use low sampling rate, so having avoided using the analog-to-digital conversion being integrated into microprocessor
Device, such as 16 bit pads with 50kHz sample frequencys.However, by by such analog-digital converter and lack sampling method
Combination, can eliminate the limitation.
There is provided bandpass filter in the advantageous embodiment of the measurement apparatus of the present invention, it is used to make preset frequency model
Enclose by the frequency with filtering more than the measurement signal frequency of measurement signal.Especially, bandpass filter is implemented as making entirely
Scheduled frequency range passes through.Bandpass filter with these features can be broadband band-pass filter.Exported by frequency mixer
Thus high-frequency harmonic is filtered out, while passing through whole intermediate-freuqncy signal.It is this compared with conventional use of narrow band filter
Broadband filter includes advantages below：It need not be tuned to the expected frequency of intermediate-freuqncy signal in production period.Which reduce
Construct fill level measurement apparatus needed for time and complexity, and further obviate to it is Special Automatic tuning feature and/
Or the need for active power filtering part.Select bandpass filter so that what the bandpass filter was used independently of intermediate-freuqncy signal
Signal form, and need not make manually and/or in the case of accurate adjustment and/or tunable bandpass filter in including
The frequency range of frequency signal passes through.
In the further development of advantageous embodiment, the bandpass filter is implemented as making to correspond to the predetermined frequency
The frequency range of rate scope passes through, wherein the frequency range is less than the half of the sample frequency of the analog-digital converter.Therefore,
Undesirable aliasing effect can be excluded from digitized intermediate-freuqncy signal.
In one embodiment of the invention, measurement apparatus is the fill level measurement apparatus based on pulse radar, wherein
Local oscillator produces local oscillator signals in measurement apparatus, and provides frequency mixer, and it was used for including for receiving
The measurement signal of electromagnetic pulse sequences is mixed with local oscillator signals, and exports analog if signal.In pulse radar apparatus
In, the pulse recurrence frequency of measurement signal and local oscillator signals can be predetermined so that intermediate frequency includes predetermined frequency
Frequency in the range of rate.This makes it possible for the analog-digital converter that lack sampling is carried out using fixed sampling frequency.
In the further development of the measurement apparatus of the present invention, correspond to the expected frequency in the frequency of intermediate-freuqncy signal
In the case of, digital medium-frequency signal of the analog-digital converter output with the frequency shifted downwards relative to analog if signal frequency,
And the amplitude of the frequency displacement corresponds essentially to the sample frequency of analog-digital converter.Advantageously, believed in the digital domain by intermediate frequency
Number formed image can be displaced to so-called first Nyquist area, wherein Nyquist from so-called 3rd Nyquist area
Area (nyquist zone) is defined as the frequency model each with the bandwidth of the half corresponding to analog-digital converter sample frequency
Enclose.
There is provided variable amplifier in the further development of the measurement apparatus of the present invention, the variable amplifier connection
Between the bandpass filter and the analog-digital converter.
The present invention measurement apparatus further development in, the second bandpass filter be connected to the variable amplifier and
Between the analog-digital converter.
In the preferred embodiment of the measurement apparatus of the present invention, the analog-digital converter is directly connected to second band logical
Wave filter.The measurement sequence of element including frequency mixer, the first bandpass filter, variable amplifier and the second bandpass filter with
Analog-digital converter with low sampling rate causes to significantly reduce the power demand in measurement period together.This power, which is reduced, to be caused
Can more it be measured with identical cost of energy, so as to by using averaging, be realized with relatively low monetary cost
The accuracy of high level.
In the further development of the measurement apparatus of the present invention, microprocessor includes being used to perform digital medium-frequency signal taking out
The parts group for taking (decimation) to handle.
In the further development of the measurement apparatus of the present invention, microprocessor includes being used to put down digital medium-frequency signal
Side, LPF and the parts group for performing square root function.
In the further development of the measurement apparatus of the present invention, microprocessor is included before being used to carry out digital measuring signal
To the parts group of-inverse filtering (forward-backward filter).In this way it is possible to consider because filtering causes
Time delay.
Brief description of the drawings
The present invention is more fully described next with reference to the following drawings.Accompanying drawing is shown：
Fig. 1：The block diagram of the part of pulse radar fill level measurement apparatus is shown；
Fig. 2 a, b：Represented for the over-sampling of the analog-to-digital conversion of intermediate-freuqncy signal and the figure of lack sampling method；
Fig. 3：The block diagram of analog and digital signal process step is shown.
Embodiment
Fig. 1 shows the block diagram for the part for showing pulse radar fill level measurement apparatus 1.Show two pulse repetitions
Frequency (hereinafter referred to as " prf ") generator 2,3.Generator may be implemented as such as crystal oscillator.In pulse radar apparatus
Prf generators 2,3 generally vibrated in megahertz range, and including slightly different frequency.Prf generators 2,3 are respective
Impulse generator 4,5 is connected to, impulse generator 4,5 has predetermined according to the input signal output received from prf generators 2,3
The pulse of pulse width.Pulse width determines by impulse generator 4,5 itself, and is fixed or can be by analog configuration
Signal changes.The repetition rate of pulse is determined by prf generators 2,3.
First impulse generator 4 is connected to transmitting oscillator 6, and transmitting oscillator 6 is each for high-frequency signal to be modulated to
In pulse, high frequency waves bag is exported.The high frequency waves bag S that measurement signal S can also be characterized as is fed to coupler 8, and coupler 8 will
Ripple bag S is delivered to transmitter/receiver unit 10.Transmitter/receiver unit 10 may, for example, be antenna, but can also be used for arteries and veins
Punching is directed to the waveguide of the material interface 11 in container 12.At material interface 11, no matter ripple bag S is brought to or by antenna
Simply launch, ripple bag S runs into impedance variations, and an each ripple bag S part is reflected back toward transmitter/receiver unit 10.Ripple
The reflecting part of bag, i.e. measurement signal S reflecting part are fed to coupler 8 by transmitter/receiver unit.Then coupler 8 will
Measurement signal S is delivered to frequency mixer 9.
In frequency mixer 9, measurement signal S and so-called local oscillator signals SLOMixing, the local oscillator signals
SLOIncluding the pulsed high-frequency ripple bag produced by local oscillator 7.Local oscillator 7 is produced according to the output of the second impulse generator 5
Raw local oscillator signals SLO.The output of frequency mixer 9 is analog if signal SIF.In general, except intermediate frequency interested
Signal SIFOutside, frequency mixer 9 also exports high-frequency harmonic.These high-frequency harmonics are then filtered out by the bandpass filter 13 connected.Band
Bandpass filter 13 is broadband band logical so that whole intermediate-freuqncy signal S interestedIFPass through.Intermediate-freuqncy signal SIFIncluding expected frequency,
The most of difference on the frequency between two prf generators 2,3 of the expected frequency is determined.However, due to such as component tolerance and/or
Temperature effect, it may occur that relative to the deviation of expected frequency.Therefore, bandpass filter 13 is implemented as leading to predetermined frequency band
Cross, the predetermined frequency band, which is expanded to, to be enough to cover intermediate-freuqncy signal SIFFrequency in all possible frequency change.For example, it may be possible to
The component tolerance that can be provided by parts suppliers of scope of frequency change determine.Generally, should in pulse radar apparatus
The bandpass filter of position is to be " tuned " to intermediate-freuqncy signal S in production periodIFActual frequency narrow band filter.
Then by the intermediate-freuqncy signal S of bandpass filteringIFIt is fed to variable amplifier 14.For example, variable amplifier 14 can be put
Signal between big 0 and 20dB.This ensures analog-digital converter 16 with optimum signal intensity continuous sampling, to maximize sampling process
Precision.Specifically, for example, by intermediate-freuqncy signal SIFSignal intensity be arranged between 16mVpp and 1.8Vpp, signal is moved
Move on analog-digital converter 16 noise range of itself, so that influence of the noise to sampling precision is minimized.
Then by with second of latter linked second bandpass filter 15 to intermediate-freuqncy signal SIFCarry out bandpass filtering.Second
Bandpass filter 15 is used for the frequency range for limiting signal to be sampled, to prepare lack sampling.Second bandpass filtering is especially limited
The noise contribution of various other reception sidepiece parts has been made, and has ensured intermediate-freuqncy signal SIFFrequency in the 3rd Nyquist area,
As explained with reference to Fig. 2 a, b.For example, the second bandpass filter 15 can be 4 rank wave filters.Present in this embodiment
A series of parts eliminate to prepare to provide for the signal of analog-to-digital conversion such as in conventional fill level radar installations
Necessity of typical logarithm device.This further reduces being produced into for the power consumption needed for measurement period and measurement apparatus 1
This.
Analog-digital converter 16 is the conventional analog-digital converter being typically included on microprocessor 17.Such converter
An example be simple 16 bit pad sampled under 50kHz.After the second bandpass filter 14, typically
Intermediate-freuqncy signal SIFAbout 60kHz centre frequency and 2 or 3kHz bandwidth can be included.According to for converting analog signals into
The Nyquist-Shaimon sampling thheorem of numeric field, it is necessary to be at least twice of sample frequency pair of analog signal frequency itself
Analog signal is sampled.It is any uncertain without introducing that the information included in the signal only can be now extracted completely
Property.By to analog if signal SIFThe uncertainty for carrying out lack sampling introducing is related to sampled signal SIFFrequency displacement copy go out
It is existing.
Fig. 2 a are shown for intermediate-freuqncy signal SIFThe figure of oversampler method of analog-to-digital conversion represent.In fig. 2 a, edge
Frequency axis and show the first two Nyquist area N1, N2.First area N1 is shielded to indicate with sample frequency fsWhat sampling was produced
Purpose Nyquist area.Intermediate-freuqncy signal SIFIn the frequency band around dotted line 18.Here sample frequency fsMeet Nyquist-
The requirement of Shannon's sampling theorem.That is, sample frequency fsAt least analog if signal SIFTwice of frequency.As a result,
The digital medium-frequency signal S obtained by samplingIFIt is maintained in the first Nyquist area N1, and is not introduced into uncertainty.
In figure 2b, show for intermediate-freuqncy signal SIFThe figure of lack sampling method of analog-to-digital conversion represent.Here, in
Frequency signal SIFIt is comprised in again in the frequency band of dotted line 18.However, due to sample frequency fsIt is much lower, so intermediate-freuqncy signal
SIFIn the 3rd Nyquist area N3.When analog-digital converter 16 is to analog signal SIFWhen being sampled, as shown in arrow 19,
Intermediate-freuqncy signal SIFImage appear in the first Nyquist area N1.Can be by such as the digital processing technology with reference to described in Fig. 3
Eliminate by forming intermediate frequency signal SIFImage or copy and the uncertainty that introduces.Especially, numeral can be performed low
Pass filter, this eliminates intermediate-freuqncy signal SIFAny upper frequency copy.
Fig. 3 shows the block diagram for showing analog and digital signal process step.In analog side, previously described second band logical
The receiving intermediate frequency signal S of wave filter 15IFAnd it is fed to microprocessor 17.Microprocessor 17 includes being used for intermediate-freuqncy signal SIF
The standard module converter 16 sampled.Digital medium-frequency signal is output to digital processing block 24 by analog-digital converter 16.Numeral
Process block 24 includes making intermediate-freuqncy signal S firstIFSquare parts group 20 so that whole signal SIFInto positive amplitude range.
Then, second component group 21 is used for the intermediate-freuqncy signal S after making squareIFSignal intensity double.Then, signal SIFCan be low
Pass filter 22, then can carry out square root 23.These digital processing steps cause to produce envelope, then can be to the envelope
Line is estimated, to determine measurement signal S flight time and/or from transmitter/receiver unit 10 to the distance of material interface 11.
In order to reduce the calculating requirement of these digital processing technologies, signal can be performed in addition and taken out before digital low-pass filtering 22 is performed
Take.Further, since LPF 22 may cause to intermediate-freuqncy signal SIFUndesirable delay, it is possible to provide for letter
Number SIFTo-the parts group that filters backward before carrying out, so as to eliminate the delay.
Reference character list
1 fill level measurement apparatus
2 the oneth prf generators
3 the 2nd prf generators
4 first impulse generators
5 second impulse generators
6 transmitting oscillators
7 local oscillators
8 couplers
9 frequency mixers
10 transmitter/receiver units
11 material interfaces
12 containers
13 first bandpass filters
14 variable amplifiers
15 second bandpass filters
16 analog-digital converters
17 microprocessors
The centre frequency of 18 intermediate-freuqncy signals
The arrow of 19 display lack sampling frequency displacements
20 squarers
21 amplifiers
22 wave digital lowpass filters
23 square roots
24 digital processing blocks
S measurement signals
SIFIntermediate-freuqncy signal
N1, N2, N3, N4 Nyquist area
fsSample frequency
Claims (12)
1. one kind is used for the measurement apparatus that the fill level (11) of the material in container (12) is measured based on time-of-flight
(1), including for generating, launching and receiving measurement signal (S), and it is further used for the measurement signal (S) being converted into mould
Intend intermediate-freuqncy signal (SIF) part (2-9), the intermediate-freuqncy signal (SIF) there is the desired signal frequency in scheduled frequency range
Rate, including the information corresponding with the fill level (11) of the material in container (12),
It is characterized in that
There is provided analog-digital converter (16), the analog-digital converter (16) is used for then to the intermediate-freuqncy signal (SIF) adopted
Sample, the analog-digital converter (16) is using less than the intermediate-freuqncy signal (SIF) desired signal frequency sample frequency (fs)。
2. measurement apparatus (1) according to claim 1
Characterized in that, the analog-digital converter (16) is integrated in the microprocessor of the measurement apparatus (1) (17).
3. measurement apparatus (1) according to claim 1 or 2
It is characterized in that there is provided bandpass filter (13), the bandpass filter (13) is used to lead to the scheduled frequency range
Cross and filter the frequency of the measurement signal frequency more than the measurement signal (S).
4. the measurement apparatus (1) according at least one in preceding claims
Characterized in that, the bandpass filter (13) is implemented as leading to the frequency range corresponding to the scheduled frequency range
Cross, wherein the frequency range is less than the sample frequency (f of the analog-digital converter (16)s) half.
5. the measurement apparatus (1) according at least one in preceding claims, it is characterised in that the measurement apparatus (1)
It is the fill level measurement apparatus (1) based on pulse radar, wherein local oscillator (7) is produced in the measurement apparatus (1)
Local oscillator signals (SLO), and frequency mixer (9) is provided, the frequency mixer (9) is used to include electromagnetic pulse by what is received
The measurement signal (S) of sequence and the local oscillator signals (SLO) mixing, and export analog if signal (SIF)。
6. the measurement apparatus (1) according at least one in preceding claims, it is characterised in that in the intermediate-freuqncy signal
(SIF) frequency correspond to the expected frequency in the case of, the analog-digital converter (16) output has relative to the simulation
Intermediate-freuqncy signal (SIF) frequency from frequency to downshift digital medium-frequency signal (SIF), and the frequency displacement size substantially
Corresponding to the sample frequency (f of the analog-digital converter (16)s)。
7. the measurement apparatus (1) according at least one in preceding claims, it is characterised in that variable amplifier is provided
(14), the variable amplifier (14) is connected between the bandpass filter (13) and the analog-digital converter (16).
8. the measurement apparatus (1) according at least one in preceding claims, it is characterised in that the second bandpass filter
(15) it is connected between the variable amplifier (14) and the analog-digital converter (16).
9. the measurement apparatus (1) according at least one in preceding claims, it is characterised in that the analog-digital converter
(16) it is directly connected to second bandpass filter (15).
10. the measurement apparatus (1) according at least one in preceding claims, it is characterised in that the microprocessor
(17) include being used for the digital medium-frequency signal (SIF) perform the parts group (24) for extracting processing.
11. at least one described measurement apparatus (1) in preceding claims, it is characterised in that the microprocessor
(17) include being used for the digital medium-frequency signal (SIF) carry out square (20), LPF (22) and perform square root function
(23) parts group (24).
12. the measurement apparatus (1) according at least one in preceding claims, it is characterised in that microprocessor (17) is wrapped
Include for the digital medium-frequency signal (SIF) carry out before to-inverse filtering parts group (24).
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE102015100555.7A DE102015100555A1 (en) | 2015-01-15 | 2015-01-15 | level meter |
| DE102015100555.7 | 2015-01-15 | ||
| PCT/EP2015/079560 WO2016113052A1 (en) | 2015-01-15 | 2015-12-14 | Fill level measurement device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107209251A true CN107209251A (en) | 2017-09-26 |
| CN107209251B CN107209251B (en) | 2020-07-28 |
Family
ID=54937035
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201580073467.1A Active CN107209251B (en) | 2015-01-15 | 2015-12-14 | Filling level measuring device |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US10267666B2 (en) |
| EP (1) | EP3245537B1 (en) |
| CN (1) | CN107209251B (en) |
| DE (1) | DE102015100555A1 (en) |
| WO (1) | WO2016113052A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109632043A (en) * | 2017-10-05 | 2019-04-16 | 克洛纳股份公司 | The method and level measurement equipment for determining medium material position are measured by continuous wave radar |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102021120821B4 (en) * | 2021-08-10 | 2023-05-17 | Krohne S. A. S. | Method for increasing the quality of sampled received signals and measuring device for time domain reflectometry |
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2015
- 2015-01-15 DE DE102015100555.7A patent/DE102015100555A1/en not_active Withdrawn
- 2015-12-14 EP EP15813321.5A patent/EP3245537B1/en active Active
- 2015-12-14 US US15/543,815 patent/US10267666B2/en active Active
- 2015-12-14 WO PCT/EP2015/079560 patent/WO2016113052A1/en active Application Filing
- 2015-12-14 CN CN201580073467.1A patent/CN107209251B/en active Active
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| US20140320336A1 (en) * | 2007-08-31 | 2014-10-30 | Raymarine Uk Limited | Digital radar or sonar apparatus |
| CN101387702A (en) * | 2008-10-22 | 2009-03-18 | 东南大学 | Phase laser range finder and phase inspecting method thereof |
| CN101991437A (en) * | 2009-08-24 | 2011-03-30 | 深圳迈瑞生物医疗电子股份有限公司 | Method and device for processing signals and Doppler ultrasound system |
| EP2369362A1 (en) * | 2010-03-18 | 2011-09-28 | Siemens Milltronics Process Instruments Inc. | A receiver for a pulse-echo ranging system with digital polyphase decimation filter |
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| CN109632043B (en) * | 2017-10-05 | 2023-11-03 | 克洛纳股份公司 | Method for determining the fill level of a medium by means of continuous wave radar measurement and fill level measuring device |
Also Published As
| Publication number | Publication date |
|---|---|
| DE102015100555A1 (en) | 2016-07-21 |
| EP3245537A1 (en) | 2017-11-22 |
| WO2016113052A1 (en) | 2016-07-21 |
| US20170370761A1 (en) | 2017-12-28 |
| CN107209251B (en) | 2020-07-28 |
| US10267666B2 (en) | 2019-04-23 |
| EP3245537B1 (en) | 2022-06-29 |
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